Most likely, yes...it will protect at this temp.. This would mean then that temps. of 280-300 are a big deal. However, I believe there are local spikes of temperature that are much higher than this...especially when shutting the car off during extreme heat with no oil or coolant circulating.
quote:Originally posted by Tyrolkid:
...How true is this? Why is everyone so worried about oil temps in the 280-300 range??
Because all oil thins with temperature. About every 30F the oil thins enough that it would be equivalent to you running the next thinner grade. So if your normal OT is 200F and you run 30wt oil. At 290F you oil will be about as thin as if you were running a 5wt!
Protect is a bad choice of words because it will protect much less because it has thinned significantly. They just mean that it won't all volatize off and coke up severely. By the way, before supersyn, they used to say up to 475F. FWIW.